Spring-driven timer

ABSTRACT

A precision timer for energizing an external load at a preselected point in time, comprising: a spring-driven motor; an electric motor in winding engagement with the spring-driven motor; an electric circuit having contacts; and rotatable contact arms driven by the spring-driven motor for sequential engagement with the contacts.

United States Patent Inventor Wilhelm A. Nemetz Bridgeton, NJ. Appl. No. 823,577 Filed May 12, 1969 Patented Mar. 23, 1971 Assignee Gulf& Western Industrial Products Company Grand Rapids, Mich.

SPRING-DRIV EN TIMER 6 Claims, 2 Drawing Figs.

[1.8. CI 325/166, 325/396, 340/309.1, 58/41 Int. Cl. l-l04b 1/04 Field of Search 58/41 (A),

[56] References Cited UNITED STATES PATENTS 2,932,733 4/1960 Paulson 325/166 2,933,882 4/1960 Sonobe et al. 58/41 Primary Examiner-Robert L. Griffin Assistant Examiner-Albert J. Mayer AttorneyMeyer, Tilberry and Body ABSTRACT: A precision timer for energizing an external load at a preselected point in time, comprising: a spring-driven motor; an electric motor in winding engagement with the springdriven motor; an electric circuit having contacts; and rotatable contact arms driven by the spring-driven motor for sequential engagement with the contacts.

PATENTE0n/1R2a1sn TRANSWTTER I N VENTOR.

JW'LHELM A. NEMETZ TORNEYS SPRlNG-DRKVEEN TKMlER This invention pertains to the timer art and, more particularly, to a precision spring-driven timer having a low power consumption.

The invention is particularly applicable for use in radio callbox alarm systems and will be described with particular reference thereto; however, it is to be appreciated that the invention has broader applications and may be used whenever it is desired to energize an external load at a preselected point in time.

it has recently become a popular practice of many state highway departments to install radio callbox alarms along the roadside. These easily accessible alarms permit a motorist to summon assistance in the form of police, fire, service vehicles and the like, in the event of an accident or breakdown. The motorist, by actuating the appropriate pushbutton within the callbox, causes a coded signal to be transmitted to the respective service agency. The nature of the signal is such, that upon its receipt the service agency can determine the location of the box from which the signal originated and thereby respond to the emergency call.

The aforementioned callboxes are generally located along remote stretches of highway which are not accessible to electric service. As such, power is supplied to these call boxes by means of rechargeable batteries. Since the successful operation of a given callbox could be a matter of life or death, in the event of an automobile accident, it is critical that the state-ofcharge of the batteries be analyzed daily. Therefore, it has become desirable to install a timing device in each callbox, which at a preselected point during a 12 hour timing cycle, will transmit a signal to a remote receiver relative to the charge status of the batteries.

i'ieretofore, commercially available precision timers have been operated by synchronous AC motors. Such timers cannot be used in most callboxes because the boxes are located where electrical power is not readily available. Therefore, it has been necessary to operate the timers by using the callbox batteries. This tends to reduce the time span between battery charges and increase the possibility of a power failure, since an additional component is now being operated by the batte- The present invention contemplates a new and improved low power precision timer which overcomes the abovereferred problems and provides a spring-driven timing device which can be used where power consumption is critical and line voltage is not available.

in accordance with the present invention there is provided a timer for controlling the energization of an external load at a preselected point in time, comprising: an electric motor having an output element; the electric motor adapted to be periodically energized by an external power source; a springdriven motor having a winding element and an output element; means for drivingly connecting the output element of the electric motor to the winding element, whereby the electric motor winds the spring-driven motor when the electric motor is energized; an electric circuit adapted to be connected to an external load across the power source; the electric circuit having at least first and second contacts; a support structure having a central axis; the contacts being mounted on the support structure with the first contact being spaced a first selected distance from the axis and the second contact being spaced a second selected distance from the axis, the distances being different; first and second movable contact arms rotatable about the axis and in electrical connection with each other; the first arm having a contact engaging surface corresponding generally to the first distance; the second arm having a Contact engaging surface corresponding generally to the second distance; means for causing the first contact engaging surface to engage the first contact when the first arm is in a first preselected position; means for causing the second contact engaging surface to engage the second contact when the second arm is in a second preselected position; means for connecting the arms with the output element of the spring-driven motor; and, the connecting means including further means for causing the elements to rotate at different speeds.

The principal object of the present invention is to provide a precision timer which does not rely upon line voltage as a source of power.

Another object of the present invention is to provide a precision timer which makes use of modern electronic manufacturing techniques by employing printed circuit board components.

A further object of the present invention is to provide a precision timer which possesses-a high degree of accuracy.

A still further object of the present invention is to provide a precision timer which is reliable, easy to manufacture and tolerant of battery voltage variation.

The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:

FIG. 1 is a side elevational view, partly broken away, of a precision timer according to the preferred embodiment of the present invention; and

FIG. 2 is a font elevational view of the low power precision timer of FIG. 1, in conjunction with a radio callbox transmitter system.

Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, FIG. 2 shows a precision timer, indicated generally by the reference letter A, embodying the present invention, which is being used in a radio callbox transmitting system to periodically energize a transmitter B which sends a signal to a remote receiver C.

Referring now to FIG. 1, where in accordance with the present invention there is provided a spring-driven motor 10. The spring drive of the motor 10 is adapted to be rewound periodically by a battery-energized DC electric motor 12 which is located rearward of the spring-driven motor. A winding shaft 14 interconnects the electric motor 12 to the springdriven motor 10. Periodically, the electric motor i2 is energized for a short period by a battery D, to be described in more detail later, whereby the electric motor winds the springdriven motor 10.

Extending axially outward from the front of the springdriven motor 10 is an output element which takes the form of a pair of concentric timer shafts l6, 18 which are drivingly connected to the motor for rotation at different rates of speed; one of the shafts l8 rotating at the rate of one revolution per 60 minutes and the other of the shafts 16 rotating at the rate of one revolution per 12 hours. One of the timer shafts 18 is coaxially disposed within the other timer shaft 16, and in electrical contact therewith, thereby providing an electrically conductive path between the shafts.

Extending axially outward from the spring-driven motor 10, and secured to the front thereof, is a cylindrical circuit board support bracket 20. The support bracket 20 is coaxially disposed about the shafts 16, 18 and a nonconductive insulator 22 is provided intermediate the support bracket and the shafts. Affixed to the forward end of the support bracket 20, and coaxial therewith, is a support structure in the form of a substantially annular printed circuit board 30 having a central axis x and a plurality of electrically conductive pathways, referred to generally by the numeral 32, extending radially outward therefrom (as best shown in FIG. 2). 12 of the pathways 32 are circumferentially spaced to divide the circuit board 30 into 12, equal, hourly segments, and have inner conductive ends 34 spaced a first selected distance from the axis x and configured to form accurate bands which define 1 hour time periods. The remaining pathways 32, 60 in number, are circumferentially spaced to divide the circuit board into 60, equal, minute segments and have inner conductive ends 36 spaced a second selected distance from the axis x, which is greater than the first selected distance, to define one minute time periods. Printed on the circuit board 30, in the area defined by adjacent inner ends 34, is the face of a conventional clock indicating hours and minutes.

The pathways 32 may be comprised of any conductive material; however, in the preferred embodiment these pathways are made of a thin copper film. In order to provide adequate wear resistance and prevent oxidation of the copper pathways 32, the pathways are plated with an oxidation resistant material, such as palladium, rhodium and the like.

The outermost end of each and every pathway 32 is configured to form an outer contact end 38. In accordance with the present invention there is provided means for connecting electrical circuitry to the contact ends 38 which may take many forms, such as insulated spring clips, adjustable spring contacts, screw-type terminals and the like; however, in the preferred embodiment this takes the form of removable pins 40 adapted to be inserted in openings provided in the outer contact ends 38 which extend through the circuit board 30. The pins as may be easily inserted in the desired contact ends 38 to select a point in time at which the transmitter B is to be energized, and are removable therefrom to change selections. Leads 12 are secured to the pins 40 for connecting the timer A to the transmitter B through the battery D.

Secured to the timer shafts l6, 18 for rotation therewith are a pair of movable contact arms 50, 52; Contact arm 51) being secured to shaft 16 and contact arm 52 being secured to shaft 18. The length of the contact arms 50, 52 are such, that a contact engaging surface 54 of arm 52 rotates into and out of contact with the inner conductive ends 34 and a contact engaging surface 56 of arm 52 rotates into and out of contact with the inner conductive ends 36. As shown in FIG. 2, when the contact engaging surfaces 54, 56 are in contact with the inner ends 3 8, 36, respectively, of those pathways 32 which have a pin 461 inserted in their outer contact ends 38, a completed electrical circuit is formed between the timer A, the transmitter l3 and the battery D, whereby the transmitter is energized and a signal sent to the remote receiver C.

Reference is now made to FIGS. 1 and 2, wherein the operation of the timer A will be described in detail. Assume for purposes of explanation that it is desired to energize the transmitter B at precisely 12:32 AM. and 12:32 PM. during a 24 hour period, in order to send a signal to the remote receiver C relative to the charge status of the battery D. Pins d are inserted in the appropriate contact ends 38 corresponding to the above selected times (as best shown in FIG. 2). The pins 40 carry leads 42 which define a circuit for connecting the timer A to the transmitter B. The circuit further includes the battery D whose charge status is to be transmitted, and serves to energize the transmitter B at the preselected time.

The spring-driven motor causes the timer shafts 16, 18 and hence the contact arms 50, 52 to rotate. ln order to prevent the rotating contact arms 50, 52 from getting caught on the raised edges of the conductive pathways 32', the nonconductive portions of the printed circuit board surrounding the inner ends 3 36 of the pathways are coated with a layer of resin material 611. The depth of the resin material 60 is substantially equal to the thickness of the pathways, whereby a uniform, level surface is provided for the arms to rotate over.

The contact arms 51), 52 continue to rotate at a rate which defines a standard timing cycle of 24 hours per day. When the contact arms 50, 52 reach the preselected point in time, namely 12:32 AM. or P.M., the electrical circuit is completed and the battery D energizes the transmitter B which sends out a signal to the remote receiver C.

It is to be appreciated that while although only one pair of pins connecting the transmitter B to the timer A have been shown, it is possible to have other configurations. Thus, for example, several pairs of pins 40 may be used in order to energize the transmitter B at various preselected points in time. It would also be possible for more than one transmitter to be energized at either the same time or at varying times.

The spring-driven motor 10 is adapted to be rewound periodically by the DC electric motor 12. At preselected time intervals, the electric motor 12 is energized and rotates the winding shaft 1 1 which is connected to the spring-driven motor 10. The rotation of the shaft 141 causes the spring tension of the motor 10 to be increased, thereby assuring the continuous, accurate performance of the timer A.

In view of the foregoing, it can be readily seen that the precision timer heretofore described is a versatile device which provides a high degree of timing accuracy, yet does not rely upon line voltage as a source of power.

lclaim:

1. A timer for controlling the energization of an external load at a preselected point in time, comprising:

a. an electric motor having an output element;

b. said electric motor adapted to be periodically energized by an external power source;

0. a spring-driven motor having a winding element and an output element;

d. means for drivingly connecting said output element of said electric motor to said winding element, whereby said electric motor winds said spring-driven motor when said electric motor is energized;

e. an electric circuit adapted to be connected to an external load across said power source;

1'. said electric circuit having at least first and second contacts;

g. a support structure having a central axis;

h. said contacts being mounted on said support structure with said first contact being spaced a first selected distance from said axis and said second contact being spaced a second selected distance from said axis, said distances being different;

. first and second movable contact arms rotatable about said axis and in electrical connection with each other;

j. said first arm having a contact engaging surface corresponding generally to said first distance;

k. said second arm having a contact engaging surface corresponding generally to said second distance;

1. means for causing said first contact engaging surface to engage said first contact when said first arm is in a first preselected position;

m. means for causing said second contact engaging surface to engage said second contact when said second arm is in a second preselected position;

n. means for connecting said arms with said output element of said spring-driven motor; and

0. said connecting means including further means for causing said elements to rotate at different speeds.

2. The device defined in claim 1, wherein said contacts comprise radially extending, electrically conductive pathways having inner ends corresponding to said selected distances for engagement with said contact engaging surfaces of said contact arms and outer ends including means for connecting electrical circuitry thereto.

3. The device defined in claim 2, wherein said circuitry connecting means comprises openings in said outer ends extending through said support structure and pins releasably received in said openings and connected to said electrical circuitry.

4. The device defined in claim 2, wherein said plated with an oxidation resistant material.

5. The device defined in claim 2, wherein the portions of said support structure surrounding said pathways are coated with a layer of material, said layer having a depth substantially equal to the thickness of said pathways, whereby a uniform level surface is provided for said movable contact arms to rotate over.

6. A periodically actuated transmitter system for use with roadside radio callboxes to signal the state-of-charge of batteries used to energize such callboxes to a remote receiver which monitors numerous such signals for action thereupon, comprising:

a. an electric motor having an output element;

b. a spring-driven motor having a winding element and an output element;

c. means for drivingly connecting said output element of said electric motor to said winding element;

pathways are battery means for periodically energizing said electric motor for short periods of time, whereby said electric motor winds said spring-driven motor;

a transmitter means connected by an electric circuit across said battery for signaling the state-of-charge of said 5 battery; said electric circuit having at least first and second contacts;

a support structure having a central axis; and

. said contacts being mounted on said support structure with said first contact being spaced a first selected distance from said axis and said second contact being spaced at second selected distance from said axis, said distances being different;

. first and second movable contact arms rotatable about said axis and in electrical connection with each other;

. said first arm having a contact engaging surface corresponding generally to said first distance;

k. said second arm having a contact engaging surface corresponding generally to said second distance;

1. means for causing said first contact engaging surface to engage said first contact when first first arm is in a first preselected position;

m. means for causing said second contact engaging surface to engage said second contact when said second arm is in a second preselected position;

n. means for connecting said arms with said output element of said spring-driven motor;

0. said connecting means including further means for causing said element to rotate at difierent speeds; and

p. a remote receiver adapted to receive said transmitter's signal. 

1. A timer for controlling the energization of an external load at a preselected point in time, comprising: a. an electric motor having an output element; b. said electric motor adapted to be periodically energized by an external power source; c. a spring-driven motor having a winding element and an output element; d. means for drivingly connecting said output element of said electric motor to said winding element, whereby said electric motor winds said spring-driven motor when said electric motor is energized; e. an electric circuit adapted to be connected to an external load across said power source; f. said electric circuit having at least first and second contacts; g. a support structure having a central axis; h. said contacts being mounted on said support structure with said first contact being spaced a first selected distance from said axis and said second contact being spaced a second selected distance from said axis, said distances being different; i. first and second movable contact arms rotatable about said axis and in electrical connection with each other; j. said first arm having a contact engaging surface corresponding generally to said first distance; k. said second arm having a contact engaging surface corresponding generally to said second distance; l. means for causing said first contact engaging surface to engage said first contact when said first arm is in a first preselected position; m. means for causing said second contact engaging surface to engage said second contact when said second arm is in a second preselected position; n. means for connecting said arms with said output element of said spring-driven motor; and o. said connecting means including further means for causing said elements to rotate at different speeds.
 2. The device defined in claim 1, wherein said contacts comprise radially extending, electrically condUctive pathways having inner ends corresponding to said selected distances for engagement with said contact engaging surfaces of said contact arms and outer ends including means for connecting electrical circuitry thereto.
 3. The device defined in claim 2, wherein said circuitry connecting means comprises openings in said outer ends extending through said support structure and pins releasably received in said openings and connected to said electrical circuitry.
 4. The device defined in claim 2, wherein said pathways are plated with an oxidation resistant material.
 5. The device defined in claim 2, wherein the portions of said support structure surrounding said pathways are coated with a layer of material, said layer having a depth substantially equal to the thickness of said pathways, whereby a uniform level surface is provided for said movable contact arms to rotate over.
 6. A periodically actuated transmitter system for use with roadside radio callboxes to signal the state-of-charge of batteries used to energize such callboxes to a remote receiver which monitors numerous such signals for action thereupon, comprising: a. an electric motor having an output element; b. a spring-driven motor having a winding element and an output element; c. means for drivingly connecting said output element of said electric motor to said winding element; d. battery means for periodically energizing said electric motor for short periods of time, whereby said electric motor winds said spring-driven motor; e. a transmitter means connected by an electric circuit across said battery for signaling the state-of-charge of said battery; f. said electric circuit having at least first and second contacts; g. a support structure having a central axis; and h. said contacts being mounted on said support structure with said first contact being spaced a first selected distance from said axis and said second contact being spaced a second selected distance from said axis, said distances being different; i. first and second movable contact arms rotatable about said axis and in electrical connection with each other; j. said first arm having a contact engaging surface corresponding generally to said first distance; k. said second arm having a contact engaging surface corresponding generally to said second distance; l. means for causing said first contact engaging surface to engage said first contact when first first arm is in a first preselected position; m. means for causing said second contact engaging surface to engage said second contact when said second arm is in a second preselected position; n. means for connecting said arms with said output element of said spring-driven motor; o. said connecting means including further means for causing said element to rotate at different speeds; and p. a remote receiver adapted to receive said transmitter''s signal. 